private @Nullable EnumSet<E> set;

    void add(E e) {
      if (set == null) {
        set = EnumSet.of(e);
      } else {
        set.add(e);
      }
    }

    EnumSetAccumulator<E> combine(EnumSetAccumulator<E> other) {
      if (this.set == null) {
        return other;
      } else if (other.set == null) {
        return this;
      } else {
        this.set.addAll(other.set);

     */
    String getRepositoryUrl();

    /**
     * The path of the artifact relative to the repository's base URL.
     *
     * @return The path of the artifact, never {@code null}.
     */
    String getName();

    /**
     * Gets the full URL of the artifact.
     *
     * @return The full URL of the artifact, never {@code null}.
     */
    String getUrl();

   */

  /**
   * Creates a new instance with {@code null} as its detail message and no cause.
   *
   * @deprecated Prefer {@linkplain ExecutionError(Error)} a constructor that accepts a cause: Users
   *     of this class typically expect for instances to have a non-null cause. At the moment, you
   *     can <i>usually</i> still preserve behavior by passing an explicit {@code null} cause. Note,

            assertTrue(s1.isEmpty());
            // isBlank will fail if sub_authority is null, so we skip that check for s1

            // All-zero subauthorities
            byte[] ident = new byte[] { 0, 0, 0, 0, 0, 0 };
            rpc.sid_t st = buildSidT((byte) 1, ident, 0, 0);
            SID s2 = new SID(st, jcifs.SID.SID_TYPE_USE_NONE, null, null, false);
            assertFalse(s2.isEmpty());
            assertTrue(s2.isBlank());

     * @param webConfigIdList List of web configuration IDs to crawl, null for all
     * @param fileConfigIdList List of file configuration IDs to crawl, null for all
     */
    public void crawl(final String sessionId, final List<String> webConfigIdList, final List<String> fileConfigIdList) {
        final boolean runAll = webConfigIdList == null && fileConfigIdList == null;
        final List<WebConfig> webConfigList;

        if (urlQueue != null && urlQueue.getEncoding() != null) {
            urlEncoding = urlQueue.getEncoding();
        } else {
            urlEncoding = responseData.getCharSet();
        }

        // cid
        final String configId = crawlingConfig.getConfigId();
        if (configId != null) {

                    break;
                }
            }
            if (this.authMethod == null) {
                return null;
            }
            NtlmMessage message = authorization != null ? new Type2Message(Base64.decode(authorization)) : null;
            reconnect();
            if (message == null) {
                message = new Type1Message(this.transportContext);

    private var commonName: String? = null
    private var organizationalUnit: String? = null
    private val altNames = mutableListOf<String>()
    private var serialNumber: BigInteger? = null
    private var keyPair: KeyPair? = null
    private var signedBy: HeldCertificate? = null
    private var maxIntermediateCas = -1
    private var keyAlgorithm: String? = null
    private var keySize: Int = 0

    init {

        assertEquals(1, chain3.updateCallCount);
    }

    // Test addChain null handling
    public void test_addChain_withNull() {
        // ArrayUtils.addAll handles null gracefully by adding it to the array
        authenticationManager.addChain(null);

        // Verify null chain doesn't cause issues during operations
        User user = createTestUser("testuser");
        try {

    @Test
    @DisplayName("Test sign method with null request and response")
    void testSignWithNullMessages() {
        // Arrange
        int offset = 0;
        int length = testData.length;

        // Act
        signingDigest.sign(testData, offset, length, null, null);

        // Assert
        verify(signingDigest, times(1)).sign(testData, offset, length, null, null);
    }

    @Test